Do you think there is a little white fence with "The Edge of Space" written on it forming a nice little boundary so that we can put a number like 93 billion to it? Do we really think that space just stops? What is there a mile further away, or a billion miles, or 100 billion miles? Personally, I can't see how there could be a limit... Why do people struggle with the idea of infinity?
(I do have some background here - both my parents were astronomers and I grew up with black holes being discussed over dinner. No formal education, but much philosohpical stimulation...)
That's only true if you are going 'round' something surely? A straight line suggests that there is no end to it and, so, can't possibly revert to the start point. Or were you speaking metaphorically?If go far enough in a straight line in one direction, you will eventually end up back where you started. Provided you don't crash into anything.
If go far enough in a straight line in one direction, you will eventually end up back where you started.
Do you think there is a little white fence with "The Edge of Space" written on it forming a nice little boundary so that we can put a number like 93 billion to it? Do we really think that space just stops? What is there a mile further away, or a billion miles, or 100 billion miles? Personally, I can't see how there could be a limit... Why do people struggle with the idea of infinity?
(I do have some background here - both my parents were astronomers and I grew up with black holes being discussed over dinner. No formal education, but much philosohpical stimulation...)
To be a bit more precise, the universe probably has a diameter of either 9.3 X 10^33 light years, or 9 X 10^10 light years, depending on whether it is finite but unbounded.